Sigil of Myrkul

Self-mill as a resource clock rather than a payoff: each combat on your turn spends a card off your own library and checks the count, cashing four-plus creatures in the graveyard for a +1/+1 counter and deathtouch on a creature you choose. The threshold is undemanding for any deck already leaning on recursion, sacrifice, or reanimation, and clearing it is the easy part. Deathtouch is the piece worth building toward. Pointed at a big attacker or a Fight or ping outlet, it converts modest board presence into a removal valve, since any damage that creature deals becomes lethal to whatever it touches. What complicates it is that the mill never turns off; hitting four does not stop the engine, so it keeps thinning your library turn after turn, and in the wrong shell it mills you out instead of feeding you. That makes it a design meant for the graveyard-as-inventory school of black self-mill, where filling the yard is the strategy and not a toll paid to enable one. The combat buff and deathtouch are the incidental grind stapled to that plan; the counting, the milling, and the accumulating creature cards are where the deck actually lives. It sits in the lineage of black payoffs that treat feeding the graveyard as the point, with the every-turn trigger doing the slow-burn accumulation work that a one-shot reanimation spell handles all at once elsewhere.